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This paper discusses the test setup and methodology required to validate complete lift axle assembly for simulating the real time test track data. The correlation of rig vs track is discussed. The approach for reduction of validation time by eliminating few of the non-damaging tracks/events, its correlation with real life condition is discussed, and details are presented. With increased competition, vehicle development time has reduced drastically in recent past. Bench test procedure using accelerated test cycle discussed in this paper will help to reduce development time and cost. Process briefed in this paper can also be used for similar test specification for other structural parts or complete suspension system of heavy commercial vehicles.

The public transport in India is gradually shifting towards electric mobility. Long range in electric mobility can be served with High Voltage Battery (HVB), but HVB can sustain for its designed life if it’s maintained within a specific operating temperature range. Appropriate battery thermal management through Battery Cooling System (BCS) is critical for vehicle range and battery durability This work focus on two aspects, BCS sizing and its coolant flow optimization in Electric bus. BCS modelling was done in 1D CAE software. The objective is to develop a model of BCS in virtual environment to replicate the physical testing. Electric bus contain numerous battery packs and a complex piping in its cooling system. BCS sizing simulation was performed to keep the battery packs in operating temperature range.

Self-soiling or surface contamination is usual phenomenon observed during rainy season wherein dirt on road are picked by rotating wheel and later released in air as fine particles. These released dirt particles are further carried by airflow around vehicle and as a result stick on vehicle exterior surfaces leading to surface contamination. Surface dirt contamination is one of critical issues that need consideration during early phase of vehicle development as vehicle styling plays a critical role for airflow around vehicle and therefore settling of dirt on vehicle exterior surfaces. Non consideration of such aspects in design can lead to safety issues with likely non-functioning of parking sensors, camera and visibility issues through ORVM, tailgate glass etc. Hence it is important to understand physical as well as digital techniques for assessment of vehicle for surface dirt contamination.

Polymers are substituting traditional materials, such as metals, in existing as well as new applications, both for structural and aesthetic applications as they are lightweight, customizable and are easy to mould into complex shapes. With such an extensive use of polymers, there is a need to carefully scrutinize their performance to ensure reliability. This is particularly the case in the automotive and electronic industries where the aesthetic appeal of their products is of prime concern and any visible scratch damage is undesirable. Concern for aesthetics has led to a need for the quantification of visibility due to scratch damage on polymeric surfaces Many painted plastic parts used in vehicles are being replaced with the molded-in color plastics for cost reduction and also due to environmental concerns associated with solvent emissions. There are multiple methods used for scratch evaluation of polymers and paints.

In the highly competitive global automotive market and with the taste of customer becoming more refined, the need to develop high quality products and achieve product excellence in all areas to obtain market leadership is critical. Buzz, squeak and rattle (BSR) is the automotive industry term for the audible engineering challenges faced by all vehicle and component engineers. Minimizing BSR is of paramount importance when designing vehicle components and whole vehicle assemblies. Focus on BSR issues for an automobile interior component design have rapidly increased due to customer’s expectation for high quality vehicles. Also, due to advances in the reduction of vehicle interior and exterior noise, engine mounts have recently been brought to the forefront to meet the vehicle interior sound level targets. Engine mounts serve two principal functions in a vehicle, vibration isolation and engine support.

The main objective of the exhaust system is to offer a leakage proof, noise proof, safe route for exhaust gases from engine to tailpipe, where they are released into the environment, while also processing them to meet the emission norms. New stringent emission norms demand ‘near-zero’ leakage exhaust systems, throughout vehicle life bringing the joints into focus as they are highly susceptible to leakage. Needless to say, this necessitates them to endure not only structural but also the environmental loads, throughout their life. Thus, the fatigue life or durability tests become the most critical part of the exhaust system development. Test acceleration and result correlation (for life prediction), to meet the stringent project timelines and stricter environmental norms are the key considerations for developing a new testing methodology. Quality of accelerated tests is ensured by deploying all possible multiple loads, to simulate real-life conditions.

Today's automotive industry demands high quality component as well as system designs within very short period of time to provide more value added features to customers on one hand and to meet stringent safety standards on the other. To reconcile economy issues, design optimization has become a key issue. In the last few decades, many OEMs took to analytical tools like Computer-Aided-Engineering (CAE) tools in order to decrease the number of prototype builds and to speed up the time of development cycle. Although such analytical tools are relatively inexpensive to use and faster to implement as compared to the costly traditional design and testing processes: however, there are many variables that CAE tools cannot adequately consider, such as manufacturing processes, assembly, material anisotropy and residual stresses. Therefore, still smart measuring and testing techniques are required to substantiate the CAE results.

In today’s automobile market, most OEMs use manual transmission for cars. Gear Shifting is a crucial customer touch point. Any issue or inconvenience caused while shifting gears can result into customer dissatisfaction and will affect the brand image. Synchronizer is a vital subsystem for precise gear shifting mechanism. Based on vehicle application selection of synchronizer for given inertia and speed difference is a key factor which decides overall shift quality of gearbox. For more demanding driver abuse conditions like skip shifting, conventional brass synchronizers have proved inadequate for required speed difference and gear inertia, which eventually results into synchronizer crashing and affects driving performance. To increase synchronizer performance of multi-cone compact brass synchronizer, a ‘Grit blasting process’ has been added. These components tested with an accelerated test plan successfully.

Small goods carrier and passenger vehicles powered by Naturally Aspirated (NA) Direct Injection (DI) diesel engines are popular in Indian automobile market. However, they suffer from inherently high radiated noise and poorly perceived sound quality. This paper documents the steps taken to reduce the radiated noise level from such an engine through structural modifications of major noise radiating components identified in the sound power analysis. The work is summarized as follows; Baseline radiated noise measurements of power train and identification of major noise sources through sound intensity mapping and noise source ranking (NSR) in an Engine Noise Test Cell (ENTC) Design modifications for identified major sources in engine structure Vehicle level assessment of the radiated noise in a Vehicle Semi-Anechoic Chamber (VSAC) for all the design modifications. A reduction of 7 dB at hot idle and 4 - 8 dB in loaded speed sweep conditions was observed with the recommended modifications.

Basic Function: Vehicle remote is used for vehicle lock/unlock/search/Hazard lights /approach light functions for customer convenience and vehicle security system. Conventional approach: 1 Use of separate RF (Radio Frequency) receiver -Additional Cost impact. 2 High remote RF power - Reduced remote battery life and bigger remote size required 3 High sensitivity RF receiver - High cost. Low Cost approach: It involves the followings: 1 Integration of RF receiver inside the Body Control Module (BCM). 2 Low Power Remote and Optimization of Remote PCB layout to get the maximum power. 3 External wired antenna taken out from BCM and proper routine need be ensured to get the best performance. 4 BCM mounting location to get the best remote range in all vehicle directions. This paper relates to the methodology for low cost approach for the RF communication between remote transmitter and receiver with achieving the best remote performance at vehicle level condition.

Power-supply forms a key hardware block for every automotive ECU. Apart from delivering robust and reliable logic supply voltages it is also burdened with many auxiliary tasks like transient protection, good EMI/EMC performance, Power-hold function, Analog Sensor supply voltage etc. It also needs to meet all automotive norms including short to battery/ground etc. This paper discusses low cost implementation techniques which maximize the value delivered to the vehicle application at minimal cost. Innovative techniques are described for combining sensor and logic supplies wherever applicable. Hurdles faced during such circuit optimization are clearly explained along with the solutions adopted to overcome hurdles yet meeting automotive test norms. A novel low cost concept which combines transient protection as well as power-hold function (without using the conventional relay based technique) further adds value to the end application.

S.A.V.E. (SOLAR-ASSISTED VEHICLE ELECTRICAL SYSTEM) is a microcontroller-based closed loop system designed to optimize the duty cycle of alternator in conventional vehicle electrical system. This has been done by integrating a SOLAR PANEL on the rooftop of a popular hatchback. The SOLAR PANEL supplies continuous power to battery for charging thereby reducing alternator duty cycle. Consequently, in order to optimize/control alternator functioning based on demand, a microcontroller has been incorporated. S.A.V.E. consists of a microcontroller which senses the instantaneous electrical load (in terms of current & voltage drawn) from battery. The controller using the intelligent algorithm keeps on checking this real-time consumption with the threshold values & decides when to activate/deactivate alternator. Thus with this controller, a) reduction in actual CO₂ emission & consequent, and b) 6% improvement in vehicle fuel efficiency has been achieved.

In case of new generation of commercial vehicles, three shaft transmissions are designed with press fitted gears on counter shaft. It allows user to save the cost of transmission manufacturing by considerable amount. In case of heavy commercial vehicles, which are being used in abusive conditions such as mining and off-road applications, it becomes absolutely necessary to ensure that the gears press fit should withstand the continuous loads and impact loads. There are design guidelines available to ensure proper fit and torque carrying capacity between the mating parts. Still, there are gear slippage, shaft and gear breakage failures in the field. In this scenario, there is a need to develop bench test procedure which will capture such failures in the prototype stage. Looking at the failures in the field, it is necessary to capture all above hidden failures in design validation phase.

In today's scenario, most of the OEMs use manual transmissions with synchronizer gear shifting system for ease of gear shifting. It gives very high fuel efficiency. Gear shifting is a customer touch point, hence it is very important to select adequate synchronizer capacity so that it will perform in better and last longer. To test the synchronizers, there are many test methods which give the idea about life of synchronizer and its performance, in different conditions. Regular synchronizer rig tests consume lot of time in deriving the results. So it is very important to find out a way which will give same results within short time period. To carry out the short time test or accelerated test, we need to understand the effect of various factors like reflected inertia, drag torque, differential speed, synchronizing time, and gear shifting force on synchronizer capacity.

Today’s competitive market demands for low cost passenger cars with lighter, smaller size, peppy response and fuel efficient engines and having world class NVH refinement levels. For such requirements, it is essential to optimize the product starting from the design conceptual stage, considering all performance aspects. Generally, three cylinder engines, due to less reciprocating masses, compared to four-cylinder engine, are said to be fuel efficient for the same capacity. Nevertheless, NVH problems caused by inherent imbalance forces and couples remain as drawback of the three-cylinder engine. However, through optimal design of the crank train, control of cylinder to cylinder pressure variation, stiffening of the engine structure, optimizing the integration with a vehicle through proper design of mounts, NVH refinement levels can be improved.

Steering system deliver a precise directional control to the vehicle chassis and ensure the safe driving at all maneuvers. Hydraulic power assisted system (HPAS) helps drivers to steer by boosting steering assistance of the steering wheel while retaining the road feel. HPAS performance is associated with the design characteristics of rotary valve, steering, suspension, kinematics, brake, tire, vehicle speed and load transfer. Thus a detailed power steering system model is absolutely necessary to evaluate and optimize the performance characteristics. However, many components of HPAS system are proprietary in nature so it is very challenging to get component characteristic of each sub-system for the complete power steering system model. Hence, it is very important to establish a technique to extract all such influencing characteristics with available test facility.

Regular vehicle has the advantage of Engine resistance even when it is not fired, hence chances of vehicle roll back on gradients will be minimized. This is not the case for Electric vehicles, which uses an electric motor that does not have any resistance offered to wheels that prevent vehicle roll back on gradient. This leads to increased load on the conventional hydraulic brakes due to absence of engine inertia. Hence, there is a need for a low cost and reliable automatic braking system which can help in holding the vehicle and assists the driver during launch in case he need to stop at a gradient. An Electromagnetic brake (EM brake) system can be used as a solution for the above-mentioned requirement. EM brake can provide hill hold and hill assist effect in addition to automatic parking brake application when the vehicle is turned-off. This system will assist anyone who need to halt the vehicle at a gradient and then relaunch it without much struggle.

Rising environmental concerns and depleting natural resources have resulted in faster adoption of green technologies. These technologies are pushed by the government of states through certain schemes and policies as to make the orbit shift ensuring greener environment in near future. Major actions can be easily seen in transportation sector. Hybrid Electric Vehicle (EV), EV and Fuel cell EV are being deployed on roads rapidly but even though some challenges are still unsolved such as battery cost, fast charging and life cycle of the automotive battery. Automotive batteries (Lithium ions) are declared as unfit for automotive usage after the loss of 20% to 15% of their initial capacity. Still 80% to 85% of battery capacity can be utilized in stationary applications other than automotive. Stationary application doesn’t demand high current density or energy density from the battery pack as of automotive requirements.

Aerodynamics performance evaluation of passenger cars is important during early vehicle development phase as it influences fuel economy, vehicle stability and drivability. Usually during initial styling phase, scale model is prepared and tested in wind tunnel to check aerodynamic performance like drag coefficient and these are used to predict aerodynamic performance of full scale model as testing on full scale model is costly and time consuming. To ensure its correctness, it is important to understand difference in physics from scale model to full scale model. In predicting full vehicle aerodynamics performance from scale model assessment; importance of Reynolds number, effect of geometric scaling on flow i.e. flow separation and wake zone change needs to be understood and addressed. This paper discusses about effect of scaling on aerodynamic flow behavior and drag.

HVAC system design has an accountability towards acoustic comfort of passengers of a vehicle. Owing to larger cabin volume of a bus, multiple air blowers have to be installed to ensure comfort of passengers. Such multiple blowers produce significant flow induced noise inside the cabin. For commercial success, it becomes essential to predict intensity of such a flow induced noise at very early stages in product development. Conventionally sliding mesh based CFD approach is deployed to predict flow and turbulence noise around each blower. However due to complexity, this method becomes computationally intensive resulting in cost and time inefficiency. Hence it is desirable to innovate around an alternative rapid, reliable prediction method, which ensures quick turnaround of prediction.